The objective of the proposed studies is to investigate the use of antisense RNA inhibition as a method to render cells resistant to infection and replication of human immunodeficiency virus (HIV). The experimental strategy involves stable gene transfer of DNA constructs, which serve as templates for the constitutive expression of antisense RNA in the transduced cells. This approach, also termed "intracellular immunization", contrasts with the use antisense oligonucleotides. The proposed studies will focus on the design of HIV specific antisense DNA templates which will be introduced into cultured human lymphoid cell lines via retroviral vectors, and tested for their ability to inhibit the replication of HIV. The major objective of the proposed studies is to design vector systems leading to efficient expression of antisense RNA in the target cells by exploring (a) the use of three types of promoters for antisense RNA expression: mammalian RNA polymerase II, human t-RNA (pol III), and a bacteriophage T7 promoter, (b) the use of two retroviral vector systems: the previously characterized N2 vector, and double copy DC vectors, a novel type of vector which was designed to improve the expression of transduced genes. Antisense RNA inhibition mediated via stable gene transfer will be used to study the mechanism of molecular and genetic regulation of HIV. A long term objective of these studies is to develop a treatment for AIDS in which bone marrow cells derived from a patient are rendered resistant to HIV replication. Development of improved antisense RNA technologies will be particularly useful to study the mechanism of action of recessive oncogenes.